Local privilege escalation via VBS heap overflow
Published Jan 13, 2026 · Updated Jan 13, 2026
Heap-based buffer overflow in Microsoft Windows VBS Enclave allows local users with high privileges to elevate privileges. Microsoft has not disclosed the specific code locus or the operation that writes beyond the heap allocation. Exploitation requires local access and high existing privileges; successful execution grants elevated control over the affected system.
Summary
What happened
Heap-based buffer overflow in Microsoft Windows VBS Enclave allows local users with high privileges to elevate privileges. Microsoft has not disclosed the specific code locus or the operation that writes beyond the heap allocation. Exploitation requires local access and high existing privileges; successful execution grants elevated control over the affected system.
The record
- CVE
- CVE-2026-20876
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2025 (Server Core installation)
- Classifications
- CWE-122, T1068
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Jan 13, 2026CVE publishedPublication date reported by the CVE source.
- Jan 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.26100.0 <10.0.26100.32230
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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